JP2004189060A - Periphery visual recognition device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a periphery visual recognition device for a vehicle capable of suppressing heat generation by a light source to a small extent as much as possible. <P>SOLUTION: This periphery visual recognition device for the vehicle is provided with an imaging device 10 and a light emitting device 30 for lighting an imaging area. The light emitting device 30 is turned on in accordance with timing for turning on the imaging device 10 and timing for lighting an auxiliary lamp. While the light emitting device 30 is on, quantity of light of the light emitting device 30 is adjusted in accordance with brightness of the imaging area. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle surrounding visual recognition device that captures an image of a landscape around a vehicle by an imaging device installed outside the vehicle and displays the captured landscape on a display device installed inside the vehicle.
[0002]
[Prior art]
In the vehicle surrounding visual recognition device as described above, sufficient visibility may not be obtained due to lack of sensitivity at the time of night driving or the like. For example, when capturing an image of a scene including a road surface around a vehicle at night, it is difficult for light to enter the image capturing apparatus, and the image becomes rough and rough due to lack of sensitivity of the image capturing apparatus. It becomes an invisible image.
[0003]
Then, as a conventional technique, there is an imaging display device provided with a light source such as an LED that irradiates near-infrared light toward an imaging range (see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-115759
[Problems to be solved by the invention]
However, in the above-described imaging display device, the influence of heat generated by the light source becomes a problem.
[0006]
In particular, when the light source is integrated with the imaging device or the like and is provided close to the imaging device, heat generated in the light source is transmitted to the imaging device. For this reason, the heat from the light source accelerates the degree of heat rise in the imaging device, and adversely affects the imaging device that is weak to heat.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicular peripheral visual recognition device capable of suppressing heat generated by a light source as low as possible.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, an invention according to claim 1 includes an imaging device that captures a scene around a vehicle, a display device that displays a scene captured by the imaging device, and an area that is captured by the imaging device. A light source to illuminate, a driving condition obtaining unit that obtains the driving condition of the vehicle, and a control unit that controls the imaging device on and off according to the driving condition of the vehicle obtained by the driving condition obtaining unit, And the control means controls the light source to be turned on and off in accordance with the timing at which the imaging device is turned on and off.
[0009]
According to a second aspect of the present invention, the image processing apparatus further includes a photometer that measures the brightness of an image area captured by the image capturing apparatus, and the controller controls the brightness of the image area measured by the photometer. Accordingly, the light amount may be adjusted by the light source.
[0010]
The invention according to claim 3 is a display device that displays a scene captured by the imaging device, a light source that illuminates an imaging region captured by the imaging device, and a light source that illuminates the imaging region captured by the imaging device. Photometric means for measuring the brightness, and control means for controlling at least one of on / off control of the light source and light amount adjustment control by the light source according to the brightness of the imaging region measured by the photometric means, It is provided with.
[0011]
5. The apparatus according to claim 4, further comprising a night-on signal output section that outputs an on-signal at night, wherein the control unit further controls the light source according to the presence or absence of an on-signal from the night-on signal output section. May be turned on and off.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a vehicle periphery recognition device according to an embodiment of the present invention will be described. FIG. 1 is a block diagram showing the overall configuration of the vehicle periphery recognition device, FIG. 2 is a schematic diagram showing an example of installation of an imaging device 10, and FIG. 3 is a schematic diagram showing the appearance of the imaging device.
[0013]
This vehicle periphery visual recognition device includes an imaging device 10, a display device 20, a light emitting device 30, and a higher-level control unit 40.
[0014]
The imaging device 10 is installed outside the vehicle 5 and captures a scene around the vehicle 5, particularly, a scene in an area where the driver cannot visually recognize the scene from the driver's seat. In the present embodiment, the imaging device 10 is installed at a corner in front of the vehicle 5 (opposite to the driver's seat) to provide a view of the outside area of the front fender on one side of the vehicle 5 which is blind from the driver. It is assumed that imaging is performed (see FIG. 2). In the present embodiment, for example, during a period when the vehicle 5 is traveling at a low speed on a narrow road, the traveling speed of the vehicle 5 is lower than a preset reference speed in order to display a blind spot to the driver. It is assumed that during the period, an image is taken by the imaging device 10 and displayed on the display device 20.
[0015]
The imaging apparatus 10 includes an imaging element 11 such as a CDD element, an element control system circuit unit 12, an encoder 13, and a power supply system circuit unit 14. The imaging element 11, the element control system circuit section 12, the encoder 13, and the power supply circuit section 14 are fixed to the vehicle 5 in a form housed in a predetermined case body 16.
[0016]
The element control system circuit section 12 includes a drive circuit section 12a for driving the image pickup element 11 and a pre-processing circuit section 12b for performing required pre-processing on an image signal output from the image pickup element 11. .
[0017]
When power is supplied from the power supply circuit section 14, the drive circuit section 12 a drives the imaging element 11 on and off in accordance with the supply timing.
[0018]
The preprocessing circuit unit 12b performs necessary preprocessing such as noise reduction processing and amplification processing on the image signal output from the image sensor 11. The image signal preprocessed by the preprocessing circuit unit 12b is output to the encoder 13. The preprocessing circuit section 12b includes an auto gain coat roll (AGC) circuit section 12c as one of the constituent elements. The AGC circuit unit 12c has a function of performing gain adjustment so that the output level of the image signal becomes constant according to the change in the input level of the image signal when amplifying the image signal output from the image sensor 11. Have. The gain value obtained by the AGC circuit unit 12c is a value corresponding to the brightness of the imaging area imaged by the imaging device 10. Specifically, when the imaging region is relatively bright, the gain value decreases, and as the imaging region darkens, the gain value increases. That is, the AGC circuit section 12c functions as a means for measuring the brightness of the imaging area, and the gain value is given to the power supply circuit section 14 as a signal indicating the brightness of the imaging area.
[0019]
Further, the encoder 13 performs necessary signal processing on the image signal output from the element control system circuit section 12 to convert the image signal into an image signal of a predetermined signal system (for example, the NTSC system). The image signal output from the encoder 13 is output to the upper control unit 40.
[0020]
The power supply system circuit section 14 includes a power supply circuit section 14a that supplies power to the element control system circuit section 12 and the imaging element 11, and a light emission control circuit section 14b that performs light emission on / off driving of the light emitting device 30 and light amount adjustment control thereof. I have.
[0021]
The power supply circuit unit 14a receives power supply from the host control unit 40, and supplies power to the element control system circuit unit 12 and the imaging element 11 at a predetermined timing in response to a command from the host control unit 40.
[0022]
The light emission control circuit unit 14b performs power on / off driving of the light emitting device 30 in response to a light emission on / off command from the host control unit 40. Further, while the light emitting device 30 emits light, the light amount adjustment control of the light emitting device 30 is performed according to the gain value given from the AGC circuit unit 12c of the element control system circuit unit 12. That is, when the gain value is relatively large, the imaging area is relatively dark, and the level of the video signal input from the imaging element 11 to the element control system circuit section 12 is relatively small. On the other hand, when the gain value is relatively small, the imaging area is relatively bright and the level of the video signal output from the imaging element 11 is relatively large, so that the amount of light emitted by the light emitting device 30 is reduced. A light amount adjustment signal is given to the light emitting device 30. In other words, the light amount of the light emitting device 30 is adjusted so that the light emission amount increases as the gain value increases.
[0023]
Instead of performing the light amount adjustment according to the gain value from the AGC circuit unit 12c, a separate light amount measurement sensor may be provided, and the light amount adjustment may be performed according to the output value from this sensor.
[0024]
The light emitting device 30 illuminates an area imaged by the imaging device 10. In the present embodiment, the light emitting device 30 illuminates an area outside the one-side front fender of the vehicle 5.
[0025]
The light emitting device 30 includes a light emitting unit 30a such as a near-infrared LED and a light emitting drive circuit unit 30b that drives the light emitting unit 30a, and is integrated with the imaging device 10. In the present embodiment, two light-emitting devices 30 are provided (only one light-emitting device 30 is shown in FIG. 1), and each light-emitting device 30 is housed in a case body 35 and a case in which the imaging device 10 is housed. It is configured to be attached to both sides of the body 16 and integrated with the imaging device 10 (see FIG. 3).
[0026]
The light emission drive circuit unit 30b drives the light emission unit 30a on and off and adjusts the light amount thereof in response to a command from the light emission control circuit unit 14b. The light emission drive circuit section 30b is configured so that the amount of heat generated in the light emitting device 30 is proportional to the amount of light (that is, when the amount of light is adjusted to be small, the amount of heat generated in the light emitting device 30 is accordingly adjusted). For example, a circuit that drives the light emitting unit 30a by PWM by turning on / off a power supply current supplied to the light emitting unit 30a at a duty ratio corresponding to a desired light amount is used. I have.
[0027]
The higher-level control unit 40 functions as a display control unit that controls the display content of the display device 20, a function as an imaging timing control unit that determines the imaging timing, and a light emission timing that determines the light emission on / off timing of the light emitting device 30. And a function as control means.
[0028]
That is, the higher-level control unit 40 outputs an image signal captured by the imaging device 10 to the display device 20 while the imaging device 10 is capturing an image, and causes the display device 20 to display the captured image around the vehicle. .
[0029]
For example, when the higher-level control unit 40 has a navigation function of detecting the traveling position of the host vehicle and displaying the detection result, the higher-level control unit 40 displays a navigation screen based on the navigation function during the normal traveling. , And the display may be switched so that the vehicle middle image captured by the imaging device 10 is displayed on the display device 20 during the imaging by the predetermined imaging device 10.
[0030]
Further, the higher-level control unit 40 determines the imaging timing based on the detection output from the vehicle speed sensor 48.
[0031]
The vehicle speed sensor 48 has a function as a traveling state acquisition unit that acquires the traveling state of the vehicle, and is provided in the vehicle and outputs a pulse signal according to the vehicle speed. The upper control unit 40 controls the imaging device 10 to turn on and off in accordance with the traveling state of the vehicle based on the output signal from the vehicle speed sensor 48. More specifically, the vehicle speed sensor 48 calculates a vehicle speed according to a pulse signal from the vehicle speed sensor 48, determines whether the calculated vehicle speed is lower than a predetermined reference speed, When the vehicle speed is lower than the reference speed, a command to turn on the imaging device 10 is given to the imaging device 10, and when the vehicle speed is higher than the reference speed, a command to turn off the imaging device 10 is given to the imaging device 10. give. When the vehicle speed is the same as the reference vehicle speed, any command for turning off the imaging device 10 and turning on the imaging device 10 may be given.
[0032]
Further, the higher-level control unit 40 determines the light emission timing based on the on / off state of the imaging device 10 and the output signal from the light switch 49.
[0033]
The light switch 49 is a switch for turning a light provided on the vehicle 5 on and off. That is, in addition to the headlights, the vehicle 5 is provided with auxiliary lights such as a clearance lamp, a tail lamp, and a license plate. The light switch 49 is a switch for turning on or off these headlights and auxiliary lights.
[0034]
In the present embodiment, an ON signal is output from the light switch 49 when the auxiliary light is turned on (including when the auxiliary light is turned on together with the headlight), and is supplied to the host control unit 40. Of course, a configuration may be employed in which an ON signal is output when the headlights of the vehicle 5 are turned on.
[0035]
Normally, when the area around the vehicle becomes dark, the driver operates the light switch 49 to turn on the auxiliary light, or additionally turns on the headlight. For this reason, the light switch 49 functions as a night ON signal output unit that outputs an ON signal at night.
[0036]
The upper control unit 40 determines whether or not to cause the light emitting device 30 to emit light based on an on / off signal from the light switch 49 when the imaging device 10 is on. That is, when the imaging device 10 is in the off state, there is no need to illuminate the imaging region, so the light emitting device 30 is turned off. When the imaging device 10 is on, the light emitting device 30 is turned on when the light switch 49 outputs an on signal, and when the light switch 49 outputs an off signal, the light emitting device 30 is turned on. Turn off.
[0037]
The display device 20 is configured by a liquid crystal display device or the like, and performs a predetermined image display according to an image signal output from the upper control unit 40. The display device 20 is disposed at a position in the vehicle 5 that can be visually recognized by a driver, for example, between a driver's seat and an auxiliary seat.
[0038]
The operation of the vehicle periphery recognition device thus configured will be described with reference to the flowchart of FIG.
[0039]
As described above, during the period in which the vehicle 5 is traveling at a low speed on a narrow road, the vehicle surrounding visual recognition device captures an image of the outside area of the front fender on one side of the vehicle 5 that becomes a blind spot, and It is assumed that the display device 20 in the vehicle is configured to display the information.
[0040]
That is, when the vehicle 5 is traveling at a normal speed (a speed higher than the reference speed), the vehicle-periphery visual recognition device determines that the vehicle speed falls below the reference speed based on the output signal from the vehicle speed sensor 48 in step S1. Is determined. When the vehicle speed falls below the reference speed, the process proceeds to the next step S2, the imaging device 10 is turned on, and the process proceeds to step S3.
[0041]
In step S3, it is determined based on the output signal from the light switch 49 whether the auxiliary light of the vehicle is on. If not, the process proceeds to step S7.
On the other hand, if it is in the ON state, the process proceeds to step S4, and the light emitting device 30 is turned on.
[0042]
By going through steps S2 and S3, in a relatively bright situation such as daytime, the imaging device 10 is turned on by itself, and the imaging by the imaging device 10 is performed under non-illumination (that is, under natural light). Become. Further, in a relatively dark situation such as at night, the light emitting device 30 is turned on together with the image capturing device 10, and the image capturing device 10 captures an image while the image capturing range is illuminated by the light emitting device 30.
[0043]
When the light emitting device 30 is turned on, the light emission control circuit unit 14b adjusts the light amount of the light emitting device 30 according to the gain value. For example, the light amount adjustment is performed so that the light amount of the light emitting device 30 becomes small in a dim state, while the light amount of the light emitting device 30 becomes large in a dark state.
[0044]
In step S4, after the light emitting device 30 is turned on, the process proceeds to step S5, and it is determined whether the auxiliary light is turned off. Here, when it is determined that the auxiliary light is turned off, the process proceeds to step S6, and the light emitting device 30 is turned off. That is, when the auxiliary light is turned off, the surroundings of the vehicle 5 become bright, so that the imaging device 10 performs imaging under non-illumination (that is, under natural light).
[0045]
Thereafter, the process proceeds to step S7, where it is determined whether the vehicle speed has exceeded the reference speed. If the vehicle speed has not exceeded the reference speed, the process returns to step S3. On the other hand, when it is determined that the vehicle speed has exceeded the reference speed, the process proceeds to step S8, where the imaging device 10 is turned off, and the process ends.
[0046]
The description returns to step S5. If it is determined in step S5 that the auxiliary light is not in the OFF state, the process proceeds to step S9, where it is determined whether the vehicle speed has exceeded the reference speed, and it is determined that the vehicle speed has not exceeded the reference speed. Then, the process returns to step S5. On the other hand, when it is determined that the vehicle speed has exceeded the reference speed, the process proceeds to step S10, in which the light emitting device 30 is turned off, the imaging device 10 is turned off, and the process ends.
[0047]
According to the vehicle surrounding visual recognition device configured as described above, the light emitting device 30 is turned on and off in accordance with the timing at which the imaging device 10 is turned on and off, so that the imaging device 10 is off. In this case, the light emitting device 30 is also turned off, and heat generated by the light emitting device 30 can be suppressed as low as possible.
[0048]
In addition, since the light emitting device 30 is controlled to be turned on and off in accordance with the presence or absence of an on signal from the light switch 49, which is a night on signal output unit, heat generated by the light emitting device 30 can be further reduced. In particular, during the daytime when the ambient temperature tends to be relatively high, heat generation can be suppressed and the temperature rise of the imaging device 10 can be prevented, which is effective.
[0049]
Further, since the light amount adjustment control of the light emitting device 30 is performed according to the brightness of the imaging region, the light emitting device 30 can emit light with a light amount as small as possible within a range necessary for photographing. Can be suppressed as low as possible.
[0050]
In the present embodiment, an example has been described in which a vehicle speed sensor is used as a traveling state acquisition unit and the imaging device 10 is turned on during low-speed traveling in order to perform imaging while the vehicle 5 is traveling at low speed. I can't. For example, as shown in FIG. 5, the imaging device 10 may be arranged at a position where the rear of the vehicle can be visually recognized, and an image may be taken when the vehicle retreats. In this case, a gear position sensor that outputs whether or not the gear of the vehicle has shifted to the reverse gear is used as the traveling status acquisition unit, and when it is determined that the reverse gear has been set based on the output of the sensor, the imaging device 10 Is turned on to obtain an image behind the vehicle.
[0051]
Further, in the present embodiment, the light emitting device 30 is turned on when the imaging device 10 is in the on state and the on signal is output from the light switch 49 (the lighting state of the auxiliary light). It is not necessary to satisfy both conditions, and the light emitting device 30 may be turned on when the imaging device 10 is in the on state. Further, the light emitting device 30 may be turned on when the light amount becomes equal to or less than a predetermined light amount based on the light amount measured by the light measuring means such as the AGC circuit unit 12c described above.
[0052]
Further, in the vehicle surrounding visual recognition device according to the present embodiment, an example has been described in which both the on / off control of the light emitting device 30 and the light amount adjustment control of the light emitting device 30 are incorporated, but one of these is incorporated. It may be.
[0053]
Further, each function of the higher-level control unit 40 and the light emission control circuit unit 14b in the present embodiment, that is, a function of turning on and off the imaging device 10, a function of turning on and off the light emitting device 30, and a function of adjusting the light amount of the light emitting device 30 Is not limited to the above embodiment, and may be realized by a single control unit or a plurality of control units in any combination.
[0054]
【The invention's effect】
As described above, according to the vehicle surrounding visual recognition device of the first aspect of the present invention, the light source is turned on and off in accordance with the timing at which the imaging device is turned on and off, so that the imaging device is turned off. In such a state, the light source is also turned off, and heat generated by the light source can be suppressed as low as possible.
[0055]
According to the vehicle surroundings visual recognition device of the second aspect, since the light amount adjustment control of the light source is performed according to the brightness of the imaging region, the light source can emit light at an appropriate brightness required for shooting. Thus, heat generated by the light source can be suppressed as low as possible.
[0056]
According to the vehicle surroundings visual recognition device of the third aspect, at least one of the light source on / off control and the light amount adjustment control of the light source is performed in accordance with the brightness of the imaging region. Thus, the light source can emit light, and heat generated by the light source can be suppressed as low as possible.
[0057]
Further, according to the fourth aspect of the present invention, since the light source is turned on / off in accordance with the presence / absence of an ON signal from the night ON signal output unit, heat generated by the light source can be further suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a vehicle periphery recognition device according to an embodiment of the present invention.
FIG. 2 is a diagram showing an application example of the vehicle periphery recognition device of the above.
FIG. 3 is a front view illustrating an arrangement example of an imaging device and a light emitting device.
FIG. 4 is a flowchart showing an operation of the vehicle periphery recognition device.
FIG. 5 is a diagram showing a modification of the vehicle periphery recognition device.
[Explanation of symbols]
5 Vehicle 10 Imaging device 12 Element control system circuit unit 12a Drive circuit unit 12b Preprocessing circuit unit 12c AGC circuit unit 14 Power supply system circuit unit 14a Power supply circuit unit 14b Light emission control circuit unit 20 Display device 30 Light emission device 30a Light emission unit 30b Light emission drive Circuit section 40 Host control section 48 Vehicle speed sensor 49 Light switch

Claims (4)

An imaging device for imaging a scene around the vehicle;
A display device that displays a scene captured by the imaging device;
A light source that illuminates an area imaged by the imaging device;
A driving condition obtaining means for obtaining a driving condition of the vehicle,
Control means for controlling the imaging device to be turned on and off in accordance with the traveling state of the vehicle acquired by the traveling state acquisition means;
With
The control device controls the light source to be turned on and off in accordance with a timing at which the imaging device is turned on and off. The vehicle periphery recognition device according to claim 1,
The image capturing apparatus further includes a photometric unit that measures the brightness of an image capturing area captured by the image capturing apparatus,
The control means includes:
A perimeter recognition device for a vehicle, wherein the light amount is adjusted by the light source in accordance with the brightness of the imaging area measured by the photometric unit. An imaging device for imaging a scene around the vehicle;
A display device that displays a scene captured by the imaging device;
A light source that illuminates an imaging area imaged by the imaging device;
Photometric means for photometrically measuring the brightness of the imaging area imaged by the imaging device,
Control means for controlling at least one of on / off control of the light source and light amount adjustment control by the light source in accordance with the brightness of the imaging region measured by the photometric means;
Peripheral visual recognition device for vehicles equipped with. A vehicle surrounding visual recognition device according to any one of claims 1 to 3,
It further includes a night-on signal output unit that outputs an ON signal at night,
The control means includes:
Further, a peripheral visibility device for a vehicle, wherein the light source is turned on and off in accordance with the presence or absence of an on signal from the night on signal output unit.

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